(page 3 - 931)TM 5-3895-374-24-2FILLINGHEATERWITHHEATTRANSFERFLUIDThe piping to all the system to be heated should be completedusing a good oil sealing pipe thread compound. Avoid usingpipe thread dope that has an oil base which will "wash out".CEI recommends Escoweld 7500 Epoxy by Exxon Chemical Co.After checking to be sure that there are no unplugged openingsleft in the piping, the heater and the system may be filled withheat transfer oil which meets the recommendations of our heattransfer oil specifications in Section 2.The burner should not be operated until the circulating oilsystem has been filled and the air worked out of the entire system.This can be determined by the fact that the circulating oil pumppressure is steady at 15 p.s.i. or higher (that is, the pressuredoes not drop to nearly zero and stay there for several seconds).The heater is protected by a pump pressure switch which will shutthe burner off when pump pressure drops below 10 p.s.i.Filling the heater can be done by putting the oil into theexpansion tank. The oil will enter the heater and system throughthe small trap between heater and expansion tank.When the oil is cold, it will flow rather slowly from theexpansion tank into the heater.The circulating pump (but not the burner) may be turned on duringthe time that oil is being put into heater. At first, as systemis filling, circulating pump pressure may be zero or very erratic,becoming steady at 15 p.s.i. or higher after system is filled withoil and all air is worked out.Do not be alarmed if it takes a little while to fill the system tothe point where the pump pressure is steady.In order to prevent overheating of the heater, it is importantthat the burner not be operated during the filling process.Use caution to assure that no water is introduced to the heatingoil system! Any moisture in the system will convert to steam whenthe temperature of the system begins to rise and can cause severedamage to equipment and injury to personnel.